Transgressive segregation for phenological traits in barley explained by two major QTL alleles with additivity

Quantitative trait loci (QTL) analysis can contribute to a deeper understanding of crop phenology. The parents of a barley mapping population have similar growth and development profiles, but the progeny show transgressive segregation for phenological traits. These phenotypes were measured in eight field experiments, using different planting dates over 3 years. Five QTL, on four chromosomes, were detected for anthesis date. The four maturity QTL were on the same chromosomes as the anthesis QTL. Five QTL for grain filling were detected on all chromosomes. Three QTL, on chromosomes 1H and 2H, were detected for photoperiod sensitivity. Both parents contributed higher value alleles for all traits, except for photoperiod sensitivity. QTL epistasis was not significant. Two QTL explained most of the phenotypic variation for anthesis and physiological maturity. Non‐parental combinations of alleles at these loci account for the phenotypic transgressive segregation. Candidate genes for these QTL effects are eps2S (2H) and denso (3H). QTL for other traits had smaller effects and were coincident with genes and/or QTL for the same traits reported in other germplasm.